On Mon, Feb 23, 2009 at 10:22 AM, Stefan Reinauer <stepan at coresystems.de> wrote:
> On 23.02.2009 18:04 Uhr, Myles Watson wrote:
>> I implemented the *_PLUGIN_SUPPORT config options for v3. I thought
>> it was simple since I was just enabling the defines already in the
>> code. In retrospect I may have implemented them backward.
>>>> The space in the ROM consumed by PLUGIN_SUPPORT is very small if you
>> already have support for that bus. If you don't have support for the
>> bus it could be significant. I wanted to make it so that e.g.
>> HYPERTRANSPORT_PLUGIN_SUPPORT was the default if you had
>> HYPERTRANSPORT_SUPPORT. I'd also like people to be able to select
>> CARDBUS_PLUGIN_SUPPORT or NO_CARDBUS_PLUGIN_SUPPORT.
>>> How much code do all those "plugins" together consume, given you have a
> system with none of that buses in the dts?
Coreboot ROM Image (QEMU) with no plugin support:
normal/option_table (932 bytes @0x50);loadaddress 0x0 entry 0x0
normal/initram/segment0 (440 bytes @0x450);loadaddress 0x0 entry 0x0x20
normal/stage2/segment0 (194780 bytes, zeroes compressed to 1 bytes
@0x660);loadaddress 0x0xd130 entry 0x0x2000
normal/stage2/segment1 (35188 bytes, lzma compressed to 18410 bytes
@0x6c0);loadaddress 0x0x2000 entry 0x0x2000
normal/stage2/segment2 (6076 bytes, lzma compressed to 360 bytes
@0x4f00);loadaddress 0x0xb974 entry 0x0x2000
bootblock (20480 bytes @0x3b000)
Total size = 41071B 40KB (0xa06f)
Coreboot ROM Image with all plugins:
normal/option_table (932 bytes @0x50);loadaddress 0x0 entry 0x0
normal/initram/segment0 (440 bytes @0x450);loadaddress 0x0 entry 0x0x20
normal/stage2/segment0 (194784 bytes, zeroes compressed to 1 bytes
@0x660);loadaddress 0x0xe1c0 entry 0x0x2000
normal/stage2/segment1 (39340 bytes, lzma compressed to 20416 bytes
@0x6c0);loadaddress 0x0x2000 entry 0x0x2000
normal/stage2/segment2 (6164 bytes, lzma compressed to 376 bytes
@0x56d0);loadaddress 0x0xc9ac entry 0x0x2000
bootblock (20480 bytes @0x3b000)
Total size = 43093B 42KB (0xa855)
It looks like about 2K. In order for it to build I had to define a
few HT-specific things and put in an empty mainboard.h, but it won't
be hard if we want to make it the default to always include all buses.
>> Maybe we could get rid of the *PLUGIN_SUPPORT options all together and
>> just allow the developer to select CARDBUS_SUPPORT or
>> REMOVE_CARDBUS_SUPPORT directly? We don't want people to deselect
>> HYPERTRANSPORT_SUPPORT when they have an Opteron, though.
>>>> If we're talking about a significant amount of code that is disabled, I
> tend to agree. On the other hand, Ron brought up the very valuable point
> that we want to try remove as many conditional compilations as possible
> to keep the code simple (and: testable)
the fewer #ifdefs the better for me too.
>> Could I get some feedback on what people want? It's very low on my
>> priority list, but I'm willing to take ownership since I put it there.
>>> Sure.. :-)
Thanks,
Myles